convert recursive array of object to nested or recursive object in javascript

Question

I have recursive array of object collection which need to convert to object,

I tried something like below but I want dynamically.

Can anyone give suggestions or share your ideas it will helpful for me

let arr = list;
const jsonObj = {};
const arrayToObject = (array, keyField) =>
array.reduce((obj, item) => {
  obj[item[keyField]] = item
  return obj
}, {})
arr.forEach((item) => {
  jsonObj[item.key] = {};
  if(item.children.length > 0) {
     jsonObj[item.key] =  arrayToObject(item.children, 'key');
  }
})

INPUT

list =  [
    {
        key: "Parent 1",
        value: "",
        children: [
            { key: 11, value: "Child 1", children: [] },
            { key: 12, value: "Child 2", children: [] }
        ]
    },
    {
        key: "Parent 2",
        value: "",
        children: [
            {
                key: 20,
                value: "",
                children: [
                    { key: 21, value: "Grand Child 1", children: [] },
                    { key: 22, value: "Grand Child 2", children: [] }
                ]
            }
        ]
    },
    {
        key: "Parent 3",
        value: "",
        children: [
            { key: 31, value: "Child 1", children: [] },
            { key: 32, value: "Child 2", children: [] }
        ]
    },
    ];

OUTPUT

{
    "Parent 1": {
        "11": "Child 1",
        "12": "Child 2",
    },
    "Parent 2": {
        "20": {
            "21": "Grand Child 1",
            "22": "Grand Child 2",          
        }
    },
    "Parent 3": {
        "31": "Child 1",
        "32": "Child 2",
    }
}

adiga · Accepted Answer · 2019-05-25 07:05:05Z

1

You could use reduce to recursively loop the array. If the current object has a non-zero children array, call transform recursively. Else, use the value for key in the accumulator

const list = [{key:"Parent 1",value:"",children:[{key:11,value:"Child 1",children:[]},{key:12,value:"Child 2",children:[]}]},{key:"Parent 2",value:"",children:[{key:20,value:"",children:[{key:21,value:"Grand Child 1",children:[]},{key:22,value:"Grand Child 2",children:[]}]}]},{key:"Parent 3",value:"",children:[{key:31,value:"Child 1",children:[]},{key:32,value:"Child 2",children:[]}]}];

function transform(array) {
  return array.reduce((r, { key, value, children }) => {
    if (children.length)
      r[key] = transform(children)
    else
      r[key] = value;
    return r;
  }, {})
}

console.log(transform(list))

One-liner using arrow function and Object.assgin():

const transform = (array) => array.reduce((r, { key, value, children }) => 
    Object.assign(r, { [key]: children.length ? transform(children): value }), {})

edited May 25, 2019 at 7:05

answered May 25, 2019 at 6:57

adiga

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Randy Over a year ago

i need vice versa output, nested object to recursive array any suggestions or ideas

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